The 2009 Tobacco Control Act charged the FDA with regulating tobacco products in the service of public health. The FDA identified key research priorities, including: understanding the diversity of tobacco products, understanding communications about tobacco products, and understanding tobacco product marketing. Broadening the traditional focus of tobacco control, the FDA calls out vulnerable populations in 11 of its 56 research priorities. Over 4 million persons receive some type of addiction treatment annually. In this vulnerable, disenfranchised and stigmatized population, where many receive health services in our public health sector, smoking rates are high (67-75%) and unyielding to prior tobacco control efforts. Because persons in this population are highly likely to smoke, they have high exposure to tobacco marketing and are likely to try, use, and adopt some emerging and potentially modified risk tobacco products. In response to PAR-12-267, the current application will recruit a national stratified random sample of 25 addiction treatment programs, where patients will be recruited to FDA research on tobacco. Patients will be recruited in three annual cross-sectional interview waves (N=1,000 per wave) and, using web-based computer assisted strategies, will be interviewed concerning use of traditional and emerging tobacco products, exposure to FDA communication and tobacco marketing, risk perception related to a range of tobacco products, and tobacco use behavior. The application uses a mixture of measures that are standard, adapted and new measures to test hypotheses that use of any tobacco products remains high over time, that use of modified risk tobacco products increases in this population over time, that exposure to FDA communications and tobacco marketing are differentially associated with level of tobacco risk-perception, and that level of risk perception s differentially associated with efforts to reduce or quit tobacco use in this population. Because this population is where smokers are concentrated, it is also where information identified in FDA priorities is most needed, but least available. The short term goal of this research is to understand use of tobacco products, marketing, messaging, and perceptions associated with those products, and their relation to tobacco use behavior in addiction treatment populations. The long-term goal is to support regulatory activity to reduce tobacco use and tobacco risks in this vulnerable population.